LONDON (Thomson Reuters Foundation) - Boko Haram Islamist militants in northern Nigeria are using children as human bombs and targeting women and girls for particularly horrific abuse, including sexual slavery, the United Nations human rights chief said on Wednesday.

Zeid Ra'ad Al Hussein told a special session of the U.N. Human Rights Council in Geneva that his office had received reports of Boko Haram using children as its first line of attack, as "expendable cannon fodder".